it's a large mass of garbage created by revelers which usually end up bobbing in the water throughout this long night. officials say almost a million krathongs are left behind after the festival each year in bangkok alone. >> translator: thais use the rivers to carry away all the bad things. as a result, there's always a large amount of garbage left over. >> reporter: to help to solve problem, state agencies are asking people to share a krathong with family or friends or make them out of natural materials. another increasingly popular option is the use of biodegradable materials such as bread. >> translator: many people are choosing bread krathongs nowadays. they are environmentally friendly, and the fish love them. >> reporter: the more technologically sophisticated can celebrate the festival online. visitors to this website can choose their favorite krathong, then add their name and wish. they can launch their krathong on this virtual river. >> any kind of real krathong will always affect the environment. the online version is cleaner and leaves nothing behind. >> reporter: but thes